This invention relates generally to roof structures and is particularly directed to an interlocking roof panel arrangement employing semi-through fasteners inserted from the underside of the roof.
In general, panel roofs include couplers for joining adjacent panels so as to provide a leak proof, mechanically strong joint. Panel couplers are designed to fill the inter-panel space so as to prevent leakage between adjacent panels while maintaining roof structural integrity. Examples of such panel couplers may be found in U.S. Pat. Nos. 1,295,538 to Lovely, 3,082,848 to Keller, and 3,102,612 to Dunnington. In the past these couplers have generally been overly complicated in structure and have required somewhat involved procedure for installation. These couplers are also generally affixed to adjacent, abutting roof panels by means of either screws or are wedged between adjacent panels in tight fitting relation and make use of one or more compressible sealant elements positioned on the outer surface to provide waterproofing. Without the use of some attachment means such as screws or rivets, the coupler has a tendency to become dislodged from tight engagement between adjacent panels due to various factors such as the temperature-dependent expansion and contraction of adjacent panels. Therefore, in order to provide a more secure mounting arrangment, the coupler has frequently been provided with a connecting pin, such as a screw or a rivet, in its outer surface. However, this arrangement is undesirable because while the coupler-panel interface may be securely sealed, the aperture required for the aforementioned mounting pin provides an additional potential source of leakage. Examples of this type of panel joint coupler may be found in U.S. Pat. Nos. 1,416,888 to Schumacher, 3,282,005 to Birdwell, 3,290,845 to Snyder, 3,791,088 to Sandow et al., 4,068,437 to Byxbe et al., and French Pat. No. 1,041,751 to Twerenbold. U.S. Pat. No. 3,886,699 to Bergmann discloses a portable building structure in which a connecting device is not positioned between adjacent panels but rather tap holes are provided through the lower surface of an upper panel through which machine bolts are inserted for engaging an upper edge portion of the next lower, adjacent panel. While apparently providing a water sealant capability, this arrangement does not securely couple adjacent panels and thus is of limited strength.
The present invention addresses the aforementioned problems of the prior art by providing an interlocking roof panel arrangement in which fasteners, or connecting pins, are inserted from the underside of the roof in order to securely draw together overlapping portions of abutting roof panels.